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Metastable and electron densities of pulsed argon plasma containing nano‐sized particles were measured by the means of Laser Absorption Spectroscopy and Microwave Interferometry, respectively. Laser Induced Fluorescence was probing the Ar* metastable axial distribution during one dust growing cycle. The experimental results of the dust‐free and dusty plasma afterglow were compared to the results obtained by a global model.

Molecular dynamics simulations have been extremely successful in the “first principles” investigation of complex plasmas. Typical examples include studies on phase transition [1], transport [2, 3] and collective behavior [4]. In this paper, we demonstrate the existence of large scale hydrodynamic phenomenology, such as the fundamental Kelvin‐Helmholtz instability in sheared flows in 2D Yukawa system by using large scale MD simulations [5] . The system size considered is macroscopic and of experimentally relevant dimensions. Our simulations capture the KH instability, its linear and nonlinear phases, nonlinear saturation leading to turbulence. Existence of inverse cascade, that is, the generation of large scale vortical flows from small scale flows is demonstrated. At the same time, we also show the appearance of dynamic, molecular‐level shear heating effects, which heats up the shear layer and thus altering the strong coupling parameter. At the nonlinear stage, while at the smallest scales, the shear heat front expands in the direction perpendicular to the flow, at the largest scale, inverse cascade continues. As our results are first‐principles‐based particle level description for large system sizes, effects predicted here using MD simulations should be demonstrable in laboratory 2D dusty plasmas.

There is currently a great interest to obtain microparticles with nanocoatings for manufacturing of abrasive, wear resistant, corrosion resistant, high strength materials for future use in various technological applications, including generation of dispersed catalyst for savings of expensive materials [1]–[4].In this regard, we carried out preliminary experiments to obtain disperse‐composite materials (DCM) using thermal spraying of dust component levitating in bulk plasma. This method does not require expensive specialized equipment and allows one to generate small particles of various materials (the average size in the range of 40–120 microns) with coatings of thickness of 10–100 nm [5].

Among dust particles of various origins collected in the MAST vessel, large quantities of carbon nanoparticles are observed. They are produced in the coldest plasma regions from the nucleation of carbonaceous species originating from physical and chemical erosion of the graphitic plasma facing components. On the other hand, laboratory plasmas studies show that in an environment of reactive carbonaceous species, complex chemical pathways lead to various molecular precursors which depend strongly on plasma conditions. The latter vary very often in a tokamak. Nevertheless, the final nanoparticles produced in laboratory plasmas and in MAST present similarities, giving indications on common growth processes in the plasma.

Silica microparticles are levitated in the sheath of rf discharge Argon plasma in a cylindrical glass chamber. The charge on a levitating dust grain is determined by measuring the electric field strength near the sheath with the help of a cylindrical Langmuir probe. The phase transition from a highly disordered state of charged microparticles (fluid state) into a crystal lattice has been studied by varying the neutral gas pressure.

The dynamical properties of individual particles in a dusty plasma under microgravity conditions are investigated by means of a stereoscopic camera setup. This camera system allows the three‐dimensional reconstruction of particle trajectories in a volume of approximately (15×15×15) mm3 in three dimensions. We present measurements in two different regions of a dust cloud on parabolic flights. First, the force field in the void is reconstructed from probe particles in three dimensions. Second, the oscillation of particles at the outer dust cloud surface is evaluated, and the relation to dust‐density waves in the dust cloud is investigated.

The particle charge has been calculated in collisional plasma in PK‐4 experimental facility. It is shown that ion‐neutral collisions play an important role to determine particle charge in this regime. Initially the grain charge decreases and later it increases with ion collisionality index. The experimental results agree well with the analytical model for grain charging.

We demonstrate that the melting curves of various model systems of interacting particles collapse to (or are located very close to) a universal master curve on a plane of appropriately chosen scaled variables. The physics behind this universality is briefly discussed. An equation for the emerging “universal melting curve” is proposed. The obtained results can be used to approximately predict melting of various substances (including complex plasmas) in a wide range of conditions.

Molecular dynamics simulations were performed to study the particle streaming motion in a toroidal trap under the influence of gravity, ion drag, friction and interparticles forces. The resulting inhomogeneous stationary streaming motion exhibits, depending on the strength of friction, a stationary shock or the formation of an vortex flow.

Debye radius is the main quantity in plasma physics. In this paper experimental values of this quantity are presented for a number of ordered dusty structures of different composition under similar discharge conditions.

We discuss experimental results from the PK‐3 Plus facility on solid‐fluid phase transitions in complex plasmas.

In this work the interaction between macroparticles in dusty plasmas is considered. To take into account screening effects in interparticle interaction we use the method of dielectric response function. The grains are considered as dipoles due to the nonequilibrium effects in dusty plasma.

In presented work the experimental research of vacancies in crystalline dusty plasma structures was studied. The experiments were carried out in high‐frequency capacitive discharge. A dusty plasma crystal was created, and then one of its particles was removed from the structure. The evolution of vacancies was researched. The data about dynamics of individual particles of the crystal structure located near the defect were obtained. Velocity dependences on time of particles and their initial accelerations were determined. On the basis of the following data the interaction force of the particles in dusty plasma structure.

The in‐situ dust detector on board the Ulysses spacecraft has collected the most comprehensive dataset of interstellar dust (ISD) particles penetrating the heliosphere between 1992 and 2007.In 2005 we identified a shift in dust flow direction by 50°, whereas before (from 1992 to 2004) it was aligned within 20° with the direction of the undisturbed dust flow through the interstellar environment. Furthermore, in this time period the dust flux shows a steep rise, which is observed in the small particles 4 months ahead of an increase in the larger particle flux. These variations of the dust flux and angular distribution can only be understood in terms of the grain interaction with the heliospheric plasma environment.

Nonplanar (viz. cylindrical and spherical) electro‐acoustic [dust‐ion‐acoustic (DIA) and dust‐acoustic (DA)] shock waves have been investigated by employing the reductive perturbation method. The dust charge fluctuation (strong correlation among highly charged dust) is the source of dissipation, and is responsible for the formation of the DIA (DA) shock structures. The effects of cylindrical and spherical geometries on the time evolution of DIA and DA shock structures are examined and identified. The combined effects of vortex‐like electron distribution and dust charge fluctuation (dust‐correlation and effective dust‐temperature) on the basic features of nonplanar DIA (DA) shock waves are pinpointed. The implications of our results in laboratory dusty plasma experiments are briefly discussed.

Vortices are an attractive expression of the non‐linear dynamics of fluids along with plasmas. Nebbat and Annou (c.f.Ref.[1]) proposed a time dependent non‐linear model that considers vortices as a consequence of an instability. The model is augmented hereafter to incorporate the gravitational grain‐grain attraction. The effect of the latter parameter is investigated.

Experimental and numerical study of positive column of glow discharge in air with disperse micron size particles is carried out with the aim to describe changes of plasma parameters and electric field configuration induced by cloud of particles.

The dusty plasma and turbulent plasma properties in the vicinity of Jupiter and particularly inside the Ganymede magnetosphere can be a key parameters for understanding the plasma processes The complex system magnetic and electric field inside the Jowian magnetosphere can drive electrojet. If these currents exceed a certain critical amplitude, a streaming instability called the Farley‐Buneman or a collisional two‐stream instability develops. This instability grows more rapidly at shorter wavelengths and the waves propagate nearly perpendicular to the magnetic field. It is well known that even system with finite number of interacting waves can realize a turbulent state in active media. In such cases, when the number of cooperating waves remains small due to a competition of processes of their instability and attenuation, the turbulence appears in the result of their stochastic behavior. We study of nonlinear stabilization and influence of the dust component, conditions of stochasticity and the different re...

Polarization of plasma surrounding a negatively charged dust particle is estimated with the help of Monte Carlo simulation of ion trajectories in the electric field of the dust particle and an external electric field. It is shown that for a small external electric field the dipole moment that is formed in plasma around the dust particle does not depend on the charge of the dust particle. For some values of the electric field the dipole moment has a maximum depending on gas density, and the dipole moment is decreasing for higher electric fields.

Real plasmas are often caracterized by the presence of excess energetic particle populations, resulting in a long‐tailed non‐Maxwellian distribution. In Space plasma physics, this phenomenon is usually modelled via a kappa‐type distribution. This presentation is dedicated to an investigation, from first principles, of the effect of superthermality on the characteristics of dusty plasma modes. We employ a kappa distribution function to model the superthermality of the background components (electrons and/or ions). Background superthermality is shown to modify the charge screening mechanism in dusty plasmas, thus affecting the linear dispersion laws of both low‐and higher frequency DP modes substantially. Various experimentally observed effects may thus be interpreted as manifestations of superthermality. Focusing on the features of nonlinear excitations (solitons) as they occur in different dusty plasma modes, we investigate the role of superthermality in their propagation dynamics (existence laws, stability profile) and characteristics (geometry).

Using a fluid model, the plasma densities, electron temperature and ion Mach number in front of a powered electrode in different plasma discharges is computed. The dust charge is computed using OML theory for Maxwellian electrons and ions distributed according to a shifted-Maxwellian. By assuming force balance between gravity and the electrostatic force, the dust levitation height is obtained. The importance of the dust charge variation is investigated.

The influence of the rf amplitude on an extended wave field of dust density waves is examined. It is found that there is a sudden fall‐off of the horizontal coherence and in the defect density when the amplitude is varied.

Charged colloidal dispersions and complex plasmas share the classical many‐body character of strongly coupled systems but differ in their dynamics, which is overdamped in the colloidal and almost ballistic in the complex plasma case. In this paper, we shall discuss basic properties of charged colloids and emphasize in particular their link to complex plasmas. Similarities and differences between colloids and complex plasmas are discussed. In particular, the charging process in colloidal suspensions, their interactions and the Brownian dynamics is outlined.

Dust grains are exposed to high‐energy electrons in different plasma environments. We have developed the numerical model that provides a description of the electron‐solid (represented by grain surface) interaction. The model fits the experimental data from spherical samples of different materials rather well, however, dust grains in space are often edgy and coarse. Thus we extended grain geometry in the model to cubes as a first approximation of irregular surface.

The dynamics of dust particles in an rf discharge were investigated using computer simulation in the frame of the two‐drmensKmal model. The molecular dynamics method is used to describe the motion of dust particles and rf discharge is described by PIC/MCC method. The simulation results have shown that dust particles are trapped in locations where the forces acting on them are balanced. The equilibrium configuration of particles studied depending on their size and different pressures of neutral gas in microgravity conditions. It is shown that dust particles lead to a decrease in the jump of the mean potential in the electrode layers and a sufficiently large particles can significantly alter plasma parameters in the discharge.

We developed a model for the nucleation, growth and transport of carbonaceous dust particles in a non‐reactive gas dc discharge where the carbon source is provided by cathode sputtering. In a first part, we considered only the initial phase of the discharge when the dust charge density remains small with respect to the electron density. We found that an electric field reversal at the entrance of the negative glow region promotes trapping of negatively charged clusters and dust particles, confining them for long times in the plasma and favoring molecular growth. An essential ingredient for this process is electron attachment, which negatively charges the initially neutral clusters. We also showed that the field reversal mechanism can operate to trap negative clusters and particles under both electropositive and strongly electronegative plasma.

Interpenetration of small particles into complex plasma formed by dust grains of a larger size has been investigated under microgravity conditions at different argon pressures. It has been observed that lane formation occurs in some parametric window depending on the coupling parameter.

Kinetic processes in the smoky plasma containing metals oxides grains and lightly ionized admixture in the gas phase are considered. The kinetic equation considering change of a charge at the expense of volume processes in a gas phase, and also thermionic issue both superficial recombination and ionisation is written down.

It is shown that, during Perseid, Geminid, Orionid, and Leonid meteor showers, the excitation of low‐frequency dust acoustic perturbations by modulational instability in the Earth's ionosphere can lead to the generation of infrasonic waves. The processes accompanying the propagation of these waves in Earth's troposphere are considered, and the possibility of observing the waves from the Earth's surface is discussed, as well as the possible onset of acoustic gravitational vortex structures in the region of dust acoustic perturbations. The generation of such structures during Perseid, Geminid, Orionid, and Leonid meteor showers can show up as an increase in the intensity of green nightglow by an amount on the order of 10% and can be attributed to the formation of nonlinear (vortex) structures at altitudes of 110–120 km. Thus the modulational excitation of the dust acoustic perturbations in the ionosphere has tropospherical response: it influences physical processes and observations in Earth's troposphere.

Since the processes in dusty plasmas are rather complex, the study of charging individual dust grains within simplified conditions becomes very important. Detailed investigations and characterization of charging processes taking place not only in dusty plasmas but also in dust‐rich space plasmas are possible for example in traps where a single dust grain can be captured for a long time and its temporal evolution with respect to surrounding conditions can be continuously recorded. The specific charge, surface potential, and mass of the observed grain can be determined. The paper shows partial results on secondary emission from lunar dust LHT simulant.

This work offers a method of experimental research of mechanisms of of metal oxides charged condensed grains interaction in smoky plasma containing lightly ionized admixture of alkali metal atoms in gas phase. Describes the hardware‐software complex TERM.

Magnetized plasma filled with Nanodust is established by means of a capacitively coupled rf discharge in a low pressure (40 Pa) Argon‐Acetylne atmosphere. The growth and the size of Nanodust is monitored by Mie Ellipsometry. Without magnetic field the well known growth oscillation is observed. The Mie Ellipsometry is capable to monitor the size of the Nanodust over a long time with excellent reproducibility. The (Ψ, Δ) plot of the polarization state can be described by a single refractive index. For weak magnetization (40 mT) the dynamics of the growth oscillation doesn't change, but the frequency of the growth oscillation increases with increasing magnetic field due to a weaker confinement of the Nanodust. For higher magnetic field (0.5 T) extended Nanodust clouds an be confined for extended times. The clouds show density waves in the direction of the magnetic field. Langmuir probe measurements show, that the dust cloud exists in the center of the discharge. The discharge shows a hollow density profile with a pronounced minimum in the plasma center.

Dust particles in a plasma acquire negative charges by capturing electrons. If the dust particle density is high, a huge loss of free electrons can trigger unstable behaviors in the plasma. Several types of plasma behaviors are analyzed thanks to a high‐speed camera like dust particle growth instabilities (DPGI) and a new phenomenon called plasma spheroids. These small plasma spheroids are about a few mm, have a slightly enhanced luminosity, and are observed in the vicinity of the electrodes. Different behaviors are identified for these spheroids like a rotational motion, or a chaotic regime (fast appearance and disappearance).

A quantitative analysis is presented of the dust acoustic wave instability driven by the solar or stelar wind. This is a current‐less kinetic instability which develops in permeating plasmas, i.e.., when one quasi‐neutral electron‐ion plasma propagates through another quasi‐neutral plasma which contains dust, electrons and ions. The cometary dusty plasma in the solar wind appears to be practically always unstable.

Vertical auto‐oscillations of single particles were obtained. The amplitude of oscillations was about 1 mm, frequency 20 Hz. It was suggested that the mechanism of the maintenance of the oscillation connected with the difference between the charge of the moving particles and the charge of particles at rest. A model of the oscillations near electrode layer was constructed. This model takes into account the recharging of particles. On the basis of this model the conditions of self‐oscillation mode, was determined depending on the parameters of the surrounding plasma.

We have investigated the liquid‐like 3D Yukawa system of microparticles confined in a cubic box with the hard walls. The general reconstruction technique (see E. M. Apfelbaum, Phys. Plasmas 14, 123703 (2007)) has been applied to reconstruct the interparticle interaction potential from the obtained pair correlation function at different values of the coupling parameter Γ. It has been shown that for the cases Γ>1 when the pair correlation functions are nonmonotonic, the techniques can not be used to reconstruct the potential, while it is possible to do for the small Γ values (Γ>>1).

The dusty crystal immersed into an external electric field is considered. For simulating such systems by Monte‐Carlo methods, a numerical code is developed. It is known shown that ion density distribution shifts across the external electric field. As a result the dipole momentum of the dusty crystal is much lower than the dipole momentum of a solitary dust particle under the same conditions.

Particle Image Velocimetry (PIV) is a fluid measurement technique in which the average displacement of small groups of particles is made by comparing a pair of images that are separated in time by an interval Δt. For over a decade, a several variations of the PIV technique, e.g., two‐dimensional, stereoscopic, and tomographic PIV, have been used to characterize particle transport, instabilities, and the thermal properties of complex plasmas. This paper describes the basic principles involved in the PIV analysis technique and discusses potential future applications of PIV to the study of complex plasmas.

This paper reports the development of a three‐dimensional(3D) dust particle position diagnostic for complex plasmas. A beam produce by Light Emitting Diodes(LEDs) is formed into horizontal sheet, for the illumination of the particles. The light sheet has a vertical colour gradient across its width, from two opposing colours. The light scattered from the particles is imaged with the camera from above. The horizontal coordinates are measured from the positions on the image. The third coordinate is determined from the colour which represents a position on the gradient of the light sheet. The use of LEDs as a light source reduces a variation in Mie scattered intensity from the particles due to the particle size distribution. The variation would induce a large vertical positional error.

Strong electrostatic interaction of highly charged microparticles in complex plasma (which is common for many laboratory experiments) can significantly modify the behavior of dust acoustic waves giving rise to their transition, at large wave numbers, into a new regime similar to the dust thermal mode. Comparison with a recent wave experiment shows excellent agreement between the theory and measurements.

Spacecraft‐plasma interactions are studied in the regime relevant for Cassini during the Saturn orbit insertion (SOI) flyby. Three‐dimensional particle‐in‐cell self‐consistent code has been employed to calculate the spacecraft (SC) potential and its spatial structure in a complicated plasma environment of Saturn's magnetosphere for a wide range of distances.

Solitary inertial Alfven wave in the presence of positively and negatively charged dust particles is studied. It is found that electron density dips are formed in the super Alfvenic region and wave amplitude is increased for the case of negatively charged dust particles in comparison with positively charged dust particles in electron‐ion plasmas.

It is interesting to study the behaviour of plasma crystal formation in presence of magnetic field. For this purpose, a Molecular Dynamics (MD) code is developed. Radial Distribution Function is plotted for dusty plasma system for different values of magnetic field. The basic assumption is that the interaction potential gets modified in presence of magnetic field.

Numerical experiments are employed to study the initial stages in phase separation induced by interaction non‐additivity in binary complex plasmas (plasmas consisting two different sized dust particles). A characteristic length scale obtained from time‐dependent pair correlation functions is used to monitor the domain growth. It is found that the domain growth follows a power law with an exponent α of about 1/3, which is in a good agreement with the initial diffusive regime of phase separation.

The effect of electrostatic confinement on charging of dust grains has been studied in a dusty plasma experimental setup by applying electrostatic field to each channel of a multicusp magnetic cage. The number of charges collected by dust grains is calculated both from the amount of deflection and floating potential. The experimental results demonstrate the significant effect of confining wall potential on charging of dust grains.

In this investigation, we have studied the large amplitude solitary structures in a dusty plasmas made up of negative ions, positive ions, stationary dust and Kappa electrons. We have observed that the opposite polarity solitary potential structures exist.

The rotation of a dust cluster levitated in plasma sheath is investigated in the presence of magnetic field. In a cylindrical plasma chamber, a dust cluster is formed by micron sized dust particles and rotates under the influence of ion drag force driven by electric and magnetic field. When ion drag force is balanced with neutral drag force the cluster rotates at constant velocity. Ion temperature is determined by estimating the forces acting on the dust particle at room temperature as well as at cryogenic temperature.

The carbon encapsulated iron nanoparticles synthesis via carbon arc discharge was investigated. It has been demonstrated that there are two macroscopically adjustable parameters (iron content in anode and arc current), allowing for optimization of this process.

The parameters of the buffer plasma containing dust particles were measured by means of spectroscopic methods. The change in the emission spectrum of the buffer plasma with addition of dust was observed. It seems to relate to changing in temperature and number density of electrons due to the influence of dusts.